• Organ rejection is mainly due to cell mediated immunity (CMI) by cytotoxic T-lymphocytes and it is not antibody-mediated.

• Cortisol (a glucocorticoid) is an immunosuppressant used to reduce graft rejection risk.
Organ transplant from a monozygotic twin has a high success rate as the monozygotic twins are genetically identical, there is no immune response and therefore, the success rate is very high.

• Tissue matching is necessary for organ transplant as tissue (especially MHC/HLA matching) is crucial to minimize rejection chances.